Shoe filler



Patented Oct. 6, 1936 UNITED STATES PATENT orrlcs SHOE FILLER No Drawing. Application August '20, 1932, Serial No. 629,739

11 Claims.

. This invention relates to a shoe filler composition for filling the bottom cavity between the inner and outer soles of a shoe, and more particularly to a shoe filler for use in shoes made 5 by the so-called compo or cementing process, wherein the soles and uppers are secured together by cellulose cements involving solvents, such as pyroxylin cements and the like.

Plastic shoe fillers of the kinds now and for many years past in general commercial use, consisting mainly of comminuted body material, such as ground cork, and a sticky binder of waxtailings (usually also containing other materials), have been satisfactory for the filling of shoes lasted and fastened together by mechanical fasteners (as distinguished from cement) such as tacks, staples or stitching.

But in the assembling of shoes by the compo or cementing processes employing pyroxylin cements or other cellulose cements, which processes are increasingly coming into use, the ordinary shoe fillers containing wax-tailings are unsuitable. The cement solvent or softener dissolves certain components of the filler composition, thus rend- J ering the filler soft and mushy instead of tough, tenacious and stable as is required of good shoe filler. Moreover certain components of the shoe filler, which are dark colored, are dissolved or softened and become sufficiently fluid to penetrate the leather and/or fabric of the shoe as well as crevices, and thus not only deplete the bonding substance of the filler but also stain and disfigure the shoe and injure the materials. Also the solution of certain of the components of the filler by components of the cement destroys or diminishes the adhesive and cohesive properties of the cement which is relied upon to hold the shoe together.

It is therefore an object of this invention to make a shoe filler composition which not only possesses the usual physical attributes necessary and desirable for the purpose, but which shall also possess appropriate chemical characteristics to adapt it for use in association with shoes containing cementitious materials of the solvent-containing pyroxylin or cellulose type above mentioned. To this end I provide the sticky binder or bonding material of the filler with a protective vehicle which prevents the dissolving, penetration or permeation of the components of the binder by the solvents or fluid components contained in, or used to soften the cement in the shoe. Hence the binder of the filler, being resistant to the solvents of the cement, will properly adhere to the shoe parts, will retain its desired consistency as shoe filler both during its application to the shoe and throughout the normal period of use and wear of the shoe, and will not impair the cement nor penetrate into the shoe or stainthe leather or fabrics of which the shoe is made.

Cellulose cements of the class referred to are exemplified by 'pyroxylin, viscose, cellulose nitrates, cellulose acetates and cellulose esters.

The solvents of cellulose cements are generally characterized by containing, in their molecular structure, hydroxyl groups or substituted hydroxyl groups or ketene groups, and are exemplified by alcohols, esters and ketones.

Incarrying out the invention, any of the usual comminuted body materials may be employed, such as ground cork, sawdust, ground leather, fibres, or any of the granular or fibrous body materials commonly known in the shoe filler art.

To make the binder by which the particles of the body material are bonded together and by which the filler mass is bonded to the shoe, I prepare an adhesive binder, which contains ingredients normally soluble in the solvents of cellulose cements, treated in such manner as to be unaffected by the ester solvents or other solvents or solvent mixtures contained in the cellulose cement compositions used in cementing shoes of the compo type.

For the'main binder ingredient I preferably use a resinous material. material may be either natural or synthetically prepared, but is typified by natural rosin, and it is preferable that it shall be light colored or even colorless, such as the so-called white rosin which is commercially obtainable. But yellow or dark rosin may be perfectly satisfactory in some cases.

Resinous materials, especially in solidified masses, are usually brittle and tend to fracture readily. If used alone, therefore, particles of resinous materials, which were heated sufliciently to become adherent to the shoe would also adhere to each other and thus form solid, brittle masses, and be wholly unsuitable. When mixed with other ingredients, as hereinafter described, the mixture becomes of the proper consistency of plasticity, pliability, stickiness and toughness for use in shoe filler. Moreover, resinous materials are more or less soluble in the solvents and softeners or plasticizers which are employed in the cements. Resinous materials are not appreciably affected by semi-fluid hydrocarbons or hydrocarbon mixtures of the aliphatic series,- which will hereinafter be referred to as semi-fluid hydrocarbon, but may be effectively separated and dis- For example, the resinous 3 able to and unaffected by such organic solvent T liquids. Furthermore, owing to the characteristic extensibility of the semi-fluid hydrocarbons, they are extremely effective intimately to wet and completely to protect the filler granules of cork or other body material and the finely divided resinous particles against being attacked by the cement solvents. To fortify such protecting effect of the intervening films of semi-fluid hydrocarbon, it is desirable to employ hydrocarbons of higher molecular weights, typified for example by petrolatum, and preferably by petrolatum which has been refined to a light yellow or even bleached, if a pure White is desired. For greater uniformity, the vaseline fraction is recommended. To improve the extensibility or spreading and wetting characteristics, especially of vaselines ofthe more solid type, a normally freely liquid hydrocarbon (but preferably non-volatile at ordinary atmospheric temperatures) such as kerosene may optionally be added thereto in very small amount and provided also that such hydrocarbon does not itself contain coloring or staining mater, as commercial kerosene sometimes may. On the other hand, in the use of vaselines of the more fluid type, solid but also lubricant hydrocarbons, such as naphthalene, may be added.

It is a feature of each of the various ingredients mentioned that it is of low color-value or essentially white. It is also a characteristic property of each that it is substantially or completely inert to the organic solvent liquids generally which are used in pyroxylin or cellulose cements.

It should be noted that hydrocarbon residues which have been subjected to destructive distillation or severe heat treatments (such as wax-tailings which have heretofore been extensively employed in shoe filling compositions) are generically unsuitable for use as a protective vehicle in accordance with this invention. This is partly because such materials ordinarily are naturally dark or darkened by such treatment, and also because they are oxidized to a greater or less extent and contain by-products which are appreciably soluble in organic solvents, such as ketones, esters, etc. above mentioned. This may be demonstrated in the case of shoe filler compositions containing wax-tailings, which are residual by-products of the destructive distillation of mineral hydrocarbons. This material contains colored ingredients which present the difficulty which is sought to be overcome by the present invention, namely, softening upon contact with the organic solvents of cellulose cements, and dissolving to a sufficient extent to penetrate into and soften the cemented and molded parts of the shoe. Natural and residual asphalt residues present the same difiiculties and hence are not to be included in the terms hydrocarbons or hydrocarbon mixtures as herein employed. It may be noted, however, that it probably is not the truly hydrocarbon components of such materials which cause these difiiculties (except so far as they may be so finely di- Vided as to be entrained with the dissolved components and carried through or into the shoe structure therewith) because the semi-fluid hydrocarbons or hydrocarbon mixtures generally.

are not soluble in the solvents used in the cements.

As an example of carrying out the invention, a given quantity of white rosin may be gradually heated to a condition of fluidity and then maintained at a temperature of approximately F. for the addition of the other ingredients. Upon the basis of the quantity of rosin employed, approximately 1/20 part by weight of naphthaline maybe added. This imparts stickiness to the binder. At the temperature of the liquefied rosin, the naphthaline melts and mixes therewith. Approximately 1/'? part by Weight of petrolatum, preferably vaseline, is also added, and being more fluid than the naphthaline and also at this temperature a liquid hydrocarbon (or mixture of hydrocarbons) effectively disperses the same and constitutes the protective vehicle. Upon admixture with the fluid rosin, the more liquid vaseline, though in smaller relative proportion, appears to constitute a solvent or, dispersing vehicle and to form a continuous phase in which the rosin binder is dispersed,

, The principal consideration governing the amount of vaseline used in proportion to the amount of rosin is. that when the mixture is cold and especially when the filler is laid in the shoe bottom, the vaseline should be small enough in quantity to remain in uniform mixture with the rosin without separation. In too large amounts the vaseline tends to separate into an external phase of the mixture upon cooling. But the amount of vaseline should be large enough so that after cooling and upon reheating for spreading in the shoe bottom, a certain amount of separation of the vaseline will occur to facilitate spreading and lubrication of the spreading tool under heat. I have found that a satisfactory proportion is l/7 part of vaseline to one part of rosin.

The binder mixture as thus prepared may be used in this condition; however, in order to make the rosin less brittle, more permanently pliable, and to improve its properties as a binder, and to enable an aqueous material, such as a soap solution and/or hydrated tapioca, to be added to emulsify and puff up the mixture, it is advantageous to add a soluble oil, e. g., 10% solution of sulphonated castor oil, in the amount of part by weight to one part of rosin. Then part of a hot solution of soap and water or like emulsion is added, which is rendered miscible with the hydrocarbons by the sulphonated castor oil. At this stage also, voluminous aqueous materials may be added to impart bulk or other properties such as viscosity, adhesiveness, etc, to the mass. example, swollen or hydrated tapioca may be so added and mixed in freely; and/or an aqueous suspension of dextrine.

The composition (either with or without the soap and/ortapioca or dextrine addition) is then mixed hot and in a uniformly fluid condition with ground cork or like comminuted body material, until the binder isuniformly distributed over may be crumbled or rubbed into separate sticky,

granules. But upon compressing a mass, even in the hand or between the thumb and forefinger it,

For

On the con-' becomes uniformly integrated, and firmly resistant tofurther, distortion or: flow under pres sure. Upontearing; the granules -,apa-rti;from one another, the; binder exhibits acertain degree of stringiness; but the strings; are short.

As thus prepared, thefiller; coin-positionmay be ivena p eliminary compacting as; by shapin into sheets or; loaves.,=.ln this. form. it maybe stored and shipped. When the filler is to be: cone d tionedi for use. thegmass is heated in a steam jacketed kettle or the like, which develops the fluidity of the petrolatum component and softens the mass generally. A suitable amount may then be taken up on the end of a flat spreading knife or spatula and freely spread into the shoe bottom. If the knife is also heated the spreading is facilitated by the petrolatum which seems to be drawn to and lubricate the spreading surfaces of the knife and of the mass. The filler conforms to and fills the irregularities in the cavity of the shoe bottom and adheres intimately thereto.

In making cemented shoes, the cement for attaching the outer sole is usually applied to the previously roughened inturned edges of the upper. The shoe may be filled before the inturned edges of the upper have been roughened or after the cement has been applied to the roughened surface. This roughening is done with a rapidly revolving stiff wire brush. When the filler is applied to the shoe bottom cavity before the roughening, the exceptional adhesiveness of the filler of the present invention will hold it in the shoe bottom cavity so firmly that the roughening brush will not tear or pull it out but will rather rough off and level the edges of the filler adjacent the edges of the upper. That is, the adhesion of the filler is greater than its cohesion. Moreover, with many fillers this roughening operation is attended by an accumulation of the filler in the brush,

which necessitates constant interruption of the work to clean the brush. With the composition herein describe-d, however, such of the filler material as is removed from the shoe by the revolving brush is so lubricated that it does not remain on or between the bristles but is quickly thrown off, so that the brush clears itself automatically. When the shoe is filled after the cement has been applied to the inturned edges of the upper, it is almost impossible to avoid getting some filler, even if only a little, on the cemented surface. If ordinary fillers are used any filler that remains on the cemented surface responds so freely to the cement softeners used that the filler is spread and distributed over a large area, and sometimes stains the outer sole and the upper, as well as weakening the bond between the outer sole and the inturned edges of the upper. These objections are very marked in the case of the generally used wax-tailing fillers, but are wholly obviated by the filler of the present invention.

The roughened margins of the shoe upper may now be moistened with the cement solvent, or the fluid cement may be applied at this stage, as the case may be, so that they become adhesive, and the sole is then set in position and forced into firm contact by the application of heavy pressure. Thereupon the sole and upper are joined together and become firmly integrate-d, so that upon evaporation of the solvent, the shoe structure is complete. The solvent is repelled by the deposit of filler composition so that the latter is not softened, but upon cooling stiffens somewhat and becomes tough, resilient and yieldable to the foot of the wearer and at the same time sufiiciently elastic toremain.g-form-retaining; Moreover, "such cone sistency is substantially permanent, even. under radical atmosphericchanges, such as temperature and humidity, and is not appreciably altered in its desirable aspects by age, whether: in use or in:- storage only.

It is also. an important quality that such filler composition,- both at the.- t-ime of its. application to. the ShOGi bottom cavity and 'duringfapplication of thecement. oracement solvent; asiwell-as' when subjected to the pressure involyed iniapplyingthe sole to the shoe, is not dissolved by and does not penetrate the solvent of the cement, nor the fabric, rubber or leather of the shoe. Hence it avoids all danger of permeating and staining either the upper of the shoe or the sole, which is a serious disadvantage of shoe fillers heretofore available on the market.

I claim:

1. A shoe filler composition consisting essentially of comminuted body material, a resinous binder, a protective vehicle of semi-fluid hydro-- carbon in which the binder is dispersed, and sulphonated castor oil.

2. A shoe filler composition consisting essentially of comminuted body material, a resinous binder, a protective vehicle of semifluid hydrocarbon in which the binder is dispersed, an aqueous component, and sulphonated castor oil.

3. A shoe filler composition consisting essentially of comminuted body material, a resinous binder, a protective vehicle of semifluid hydrocarbon in which the binder is dispersed, an aqueous soap solution and sulphonated castor oil.

4. A shoe filler composition consisting essentially of comminuted body material, a resinous binder, a protective vehicle of semifluid hydrocarbon in which the binder is dispersed, an aqueous suspension of tapioca and. sulphonated castor oil.

5. A shoe filler composition consisting essentially of comminuted body material, a resinous binder, a protective vehicle of semifluid hydrocarbon in which the binder is dispersed, sulphonated castor oil, and an aqueous suspension of dextrine.

6. A shoe filler composition consisting essentially of comminuted body material, a rosin binder, a protective vehicle of semifluid hydrocarbon in which the binder is dispersed, sulphonated castor oil, an aqueous soap solution and an aqueous suspension of tapioca.

'7. A shoe filler composition, consisting essentially of a comminuted body material, a resinous binder, and a protective vehicle of semifluid paraffin hydrocarbon which is substantially insoluble in solvents of cellulose esters and inert and impermeable toward the body material and binder, said vehicle being distributed throughout the mixture in a continuous phase.

8. A shoe filler composition, consisting essentially of a comminuted body material, a resinous binder, and a protective vehicle of petroleum jelly which is substantially insoluble in solvents of cellulose esters and inert and impermeable toward the body material and binder, said vehicle being distributed throughout the mixture in a continuous phase.

9. A shoe filler composition, consisting essentially of a comminuted body material, a binder of rosin, and a protective vehicle of semifluid parafiin hydrocarbon which is substantially insoluble. in solvents of cellulose esters and inert and. impermeable toward the body material and 7 binder, said vehicle being distributed throughout the mixture in continuous phase.

10. A shoe filler composition, consisting essentially of a comminuted body material, a binder of rosin, modified with naphthalene, and a protective vehicle of semifiuid paraffin hydrocarbon which is substantially insoluble in solvents of cellulose esters and inert and impermeable toward the body material and binder,- said vehicle being distributed throughout the mixture in a'continuous phase.

11. A shoe filler composition, consisting es sentially of a comminuted body material, an emulsified resinous binder, and a protective vehicle of semifiuid parafiin hydrocarbon which is substantially insoluble in solvents of cellulose esters and inert and impermeable toward the body material and binder, said vehicle being distributed throughout the mixture in a continuous phase.

ANDREW THOMA. 

